Freezer storage container with ventilation openings

ABSTRACT

A food storage and shipping container for use in a commercial freezer is provided. The container has improved heat transfer capabilities. The container includes a box and a lid and a plurality of ventilation openings allowing improved convective heat transfer between the freezer atmosphere and food in the container.

FIELD OF THE INVENTION

The invention relates generally to containers for storage and shipmentof frozen food stuffs.

BACKGROUND OF THE INVENTION

Containers fabricated from corrugated paperboard to store and shipfrozen food are known. For example, it is known to provide a generallyrectangular box in which processed chicken is placed for transportationfrom the chicken processing plant to a freezer facility. While in thebox, the chicken is frozen at the freezer facility to a sub-zero degreeFahrenheit temperature, and subsequently shipped to a distributioncenter.

Known boxes, designated by reference numeral 10 in FIG. 1, typicallyhave two generally parallel opposing longitudinal sides 12 and twogenerally parallel opposing transverse sides 14. A preferred size forthe boxes 10 is approximately 22 inches long by 15 inches wide by 6.5inches high. However, specific dimensions may vary. The boxes 10 areheld closed by bands 16, and are stacked in layers on pallets 20.Standard pallets are 40″ wide by 48″ long, and will accommodate fiveboxes 10 per layer. Typically, the pallets are stacked with eight layersof boxes 10. The boxes 10 are preferably stacked with a small gap 22between the boxes 10 on a given layer.

It is highly desirable during the freezing process to allow air tocirculate between the boxes, to increase the convective heat transferbetween the freezer air and the boxes 10 and the contents of the boxes,and thereby expedite the freezing process. To further enhance convectiveheat transfer and expedite the freezing process, it is known to insertdividers 30 between the layers of boxes 10. The dividers 30 form aplurality of air channels 32 alternating between spacer members 34connected to a panel 36. The dividers 30 allow air to circulate betweenthe layers of boxes 10. However, dividers need to be purchased, and theprocess of inserting and removing the dividers 30 is labor intensive.Furthermore, the dividers 30 must be cleaned on a regular basis, anotherlabor intensive process. Still further, the additional handling of theboxes 10 required when the dividers 30 are used increases theopportunity for and the probability of damage to the box 10 and itscontents. It would be desirable to eliminate the need for use ofdividers in the freezing process while maintaining or reducing the timerequired to complete the freezing process.

SUMMARY OF THE INVENTION

In a first aspect, the invention is a food storage and shippingcontainer for use in a freezer. In an assembled state, the containercomprises a box generally in the shape of a parallelepiped having firstand second longitudinal side wall panels, first and second transverseside wall panels, an open top and a bottom panel. The container furthercomprises a lid sized and shaped to close the open top. At least fourventilation openings are located in the container to allow air to flowthrough the box in a first direction substantially perpendicular to thefirst and second longitudinal side walls and in a second directionsubstantially perpendicular to the transverse side walls.

In a second aspect, the invention is a food storage and shippingcontainer for use in a freezer. The container comprises a box generallyin the shape of a parallelepiped having first and second generallyparallel opposite transverse side panels, each with an upper and a loweredge. The box has first and second generally parallel oppositelongitudinal side panels, each with an upper and a lower edge. The boxincludes an opening defined by the upper edge of each of the side panelsand a generally flat bottom panel interconnecting the lower edge of eachof the side panels. The container further includes a lid sized andshaped to cover the opening. A plurality of ventilation openings in thecontainer are provided, including a first set of openings wherein eachopening defines an area lying in a plane substantially perpendicular tothe longitudinal side panels and a second set of openings, wherein eachopening defines an area lying in a plane substantially perpendicular tothe transverse side panels.

In a third aspect, the invention is a food storage and shippingcontainer for use in a freezer comprising: a box having a plurality ofside wall panels; a lid; and a ventilation hole located in a side panel.

Preferably, the box is fabricated from wax coated, corrugatedpaperboard. The container is preferably sufficiently structurally robustto allow at least six fully loaded containers to be stacked one on topof another without damaging the bottom container or its contents. Theventilation openings may be located near the lower edges of the sidepanels, with at least one ventilation opening located near the loweredge of each of the side panels. A spacer and false bottom may beprovided, sized and shaped to fit within the box and supportable by thebottom panel. The spacer has a plurality of passages allowing fluidcommunication among the container ventilation openings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For the purpose of illustrating the invention, there are shown in thedrawings an embodiment of the invention which is presently preferred; itbeing understood, however, that this invention is not limited to theprecise arrangements and instrumentalities shown. In the drawings:

FIG. 1 is a side view of a pallet loaded with a plurality of prior artcontainers stacked in multiple layers, with a divider inserted betweeneach layer of containers.

FIG. 2 is an exploded perspective view of a container in accordance witha preferred embodiment of the present invention.

FIG. 3 is an end view of the container of FIG. 2.

FIG. 4 is cross-sectional view of the container of FIGS. 2 and 3, takenalong line 4-4 of FIG. 3.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings, and particularly to FIGS. 2-4, a food storageand shipping container in accordance with the present invention isindicated generally by the reference numeral 100. The container 100 isgenerally in the shape of a parallelepiped. The container 100 comprisesa box 110 and a lid 130 and is provided with a plurality of ventilationopenings 140. More particularly, the box 110 includes first and secondgenerally parallel opposite transverse side panels 112, each having alower edge 114 and an upper edge 116. The box 110 further has first andsecond generally parallel opposite longitudinal side panels 118, eachhaving a lower edge 120 and an upper edge 122. The box 110 includes anopening 126 defined by the upper edges 116, 122 of the side panels and agenerally flat bottom panel 124 interconnecting the lower edges 114, 120of the side panels.

The lid 130 is sized and shaped to cover the opening 126. In thepreferred embodiment illustrated, the lid 130 is fully separable fromthe box 110. However, the lid 130 could be formed by one or more panelsconnected to or integral with one or more of the upper edges 116, 122and pivotable into a position to cover the opening 126.

A plurality of ventilation openings 140 in the container 100 include afirst set of openings 142. Each opening 142 defines an area lying in aplane substantially perpendicular to the longitudinal side panels 118. Asecond set of openings 144 is provided, wherein each opening 144 definesan area lying in a plane substantially perpendicular to the transverseside panels 112. The plurality of ventilation openings 140 thus allowair to flow through the box 110 in a first direction substantiallyperpendicular to the longitudinal side panels 118 as well as in a seconddirection substantially perpendicular to the transverse side panels 112.

In the embodiment illustrated, the ventilation openings 140 are locatednear the lower edges of the side panels, with at least one ventilationopening 140 located near the lower edge 114, 120 of each of the sidepanels 112, 118. With the ventilation openings located near the bottomof the box 110, it is preferable to also provide a spacer 150 and falsebottom 160, as described in detail below, in order to prevent thecontents of the container 100 from blocking the ventilation openings140. Alternatively, the ventilation openings 140 may be located atpoints on the container 100 remote from the container contents, suchthat the contents would not block the ventilation openings 140 in thatevent, the spacer 150 and false bottom 160 may be eliminated.

The ventilation openings 140 are sized to allow sufficient airflowthrough the container 100 to provide enhanced convective heat transfer,while also maintaining adequate structural strength and integrity of thecontainer 100. In one preferred embodiment, the ventilation openings 140have a combined area of at least 5 square inches.

Preferably, the box 110 is fabricated from corrugated paperboard, usingconventional box manufacturing techniques. A wax coating may be appliedto the corrugated paperboard, using conventional techniques. The lid 130is also preferably fabricated from corrugated paperboard. Otherconventional materials having appropriate strength characteristics overthe entire temperature range of the box 110 (such as certain polymericmaterials or metals) could also be used to fabricate the box 110 and lid130.

In an embodiment especially suited for storage and shipping of processedchickens, the longitudinal side panels 118 preferably have a length ofapproximately 22 inches and the transverse side panels 112 each have alength of approximately 15 inches. Accordingly, the lid has an uppersurface 132 approximately 22 inches long and 15 inches wide.

When packed with processed chickens, the container 100 will weighapproximately 40 pounds (for a packed density of approximately 32.2pounds per cubic foot of container space). Preferably, although notnecessarily, during freezing, storage, and shipping, the containers 100are stacked no less than five high, thus imposing a static load of5*40=200 pounds on each container 100 on the bottom layer. Hence, thecontainer 100 preferably is capable of supporting a static load of atleast 200 pounds distributed generally uniformly over substantially theentire upper surface of the lid. Stated otherwise, the container 100 ispreferably, although not necessarily, designed to be capable ofsupporting a load of at least 0.60 pounds per square inch applieduniformly over the lid upper surface 132. Additional structuralcapacity, allowing the containers 100 to be stacked more than five high,is desirable but not vital.

As indicated above, when the ventilation openings 140 are located nearthe bottom of the box 110, the container 100 preferably furthercomprises a spacer 150 and false bottom 160 sized and shaped to fitwithin the box 110. When installed in the box 110, the spacer 150 restsupon and is supported by the bottom panel 124. The spacer 150 is formedby a plurality of inter-engaging cross members 152 forming alattice-type structure. Each cross member 152 is provided with aplurality of passages 154 allowing fluid communication among thecontainer ventilation openings 140.

Preferably, the cross members 152 are formed from corrugated paperboardand are pivotable relative to one another to move between a collapsedconfiguration (not illustrated) and the extended configurationillustrated in FIG. 2.

The false bottom panel 160 is used in conjunction with the spacer 150.The false bottom panel 160 is sized and shaped to fit within the box 110and is supportable by the spacer 150 and is preferably fabricated fromcorrugated paperboard. The false bottom panel 160 and spacer 150function to keep the container contents away from the ventilationopenings 140, and thus prevent blockage of the ventilation openings 140by the container contents.

In use of the preferred embodiment illustrated, the spacer 150 and falsebottom 160 are placed in the bottom of the box 110. The containercontents (not illustrated) are then deposited in the box 110, and thelid 130 is put on to close the box 110. Preferably, bands are installedon the container 100 to restrain the lid 130 to the box 110. Thecontainers 110 are then shipped to a freezer facility from theprocessing plant. Preferably, the containers 110 are shipped on apallet, and, in contrast to existing procedures wherein prior to thefreezing process it is necessary to install the dividers 30 betweenlayers of prior art containers 10 (see FIG. 1), the containers 100 maybe stacked directly on top of one another.

When placed in a blast freezer (not shown) in their stacked, palletizedconfiguration, the ventilation holes 140 allow warmer air within thecontainers 100 to circulate with the cooler air of the freezer. The flowcan be induced solely by natural convection, or alternatively can be acombination of natural and forced convection, as the freezer may beequipped with one or more fans to help force cooler ambient air throughthe containers 100.

The operating temperature of the blast freezer is on the order of −25degrees Fahrenheit. The containers 100 are left in the blast freezer fora period of approximately 48 hours. While in the blast freezer, thetemperature of product stored in the containers 100 is reduced fromapproximately 30 degrees Fahrenheit to approximately −5 to −10 degreesFahrenheit.

The ventilation holes 140 provide enhanced heat transfer rates whencompared to the existing container 10 configuration (even when thedividers 30 are used), as the rate of natural convective heat transferwithin the container 100 is substantially increased because warm airwithin the container 100 comparatively readily flows out of thecontainer 100 through the ventilation openings 140 to be replaced bycooler freezer air. While the conventional dividers 30 promote enhancedconvective heat transfer on the exterior of the convention container 10(at the substantial cost of providing, installing, and removing thedividers 30), enhancing the convective heat transfer on the interior ofthe container 100 is thought to be particularly effective in reducingthe total freeze time required.

The container according to the invention provides substantially improvedheat transfer performance and consequently reduces freeze cycle times,while also eliminating the need for use of dividers in the freezingprocess. The reduced freeze cycle times provide the advantage ofreducing the risk of bacterial contamination of the food stored in thecontainer.

While the invention has been described and illustrated with respect tothe exemplary embodiments thereof, it should be understood by thoseskilled in the art that the foregoing and various other changes,omissions and additions may be made therein and thereto, without partingfrom the spirit and scope of the present invention.

1. A food storage and shipping container for use in a freezercomprising: a box generally in the shape of a parallelepiped, havingfirst and second longitudinal side wall panels, first and secondtransverse side wall panels, an open top and a bottom panel; a lid sizedand shaped to close the open top; and at least four ventilation openingslocated in the container to allow air to flow through the box in a firstdirection substantially perpendicular to the first and secondlongitudinal side walls and in a second direction substantiallyperpendicular to the transverse side walls.
 2. A food storage andshipping container for use in a freezer comprising: a box generally inthe shape of a parallelepiped, having first and second generallyparallel opposite transverse side panels, each with an upper and a loweredge; first and second generally parallel opposite longitudinal sidepanels, each with an upper and a lower edge; an opening defined by theupper edge of each of the side panels; and a generally flat bottom panelinterconnecting the lower edge of each of the side panels; a lid sizedand shaped to cover the opening; and a plurality of ventilation openingsin the container, including a first set of openings wherein each openingdefines an area lying in a plane substantially perpendicular to thelongitudinal side panels and a second set of openings wherein eachopening defines an area lying in a plane substantially perpendicular tothe transverse side panels.
 3. The container of claim 2 wherein the boxis fabricated from corrugated paperboard.
 4. The container of claim 3wherein the corrugated paperboard includes a wax coating.
 5. Thecontainer of claim 2 wherein the longitudinal side panels each have alength of approximately 22 inches and the transverse side panels eachhave a length of approximately 15 inches and the lid has an uppersurface approximately 22 inches long and 15 inches wide.
 6. Thecontainer of claim 5 wherein the container is capable of supporting astatic load of at least 200 pounds distributed generally uniformly oversubstantially the entire upper surface of the lid.
 7. The container ofclaim 5 wherein the ventilation openings have a combined area of atleast 5 square inches.
 8. The container of claim 2, wherein thecontainer is capable of supporting a load of at least 0.60 pounds persquare inch applied uniformly over the upper surface of the lid.
 9. Thecontainer of claim 2, wherein the ventilation openings are located nearthe lower edges of the side panels, with at least one ventilationopening located near the lower edge of each of the side panels.
 10. Thecontainer of claim 9 further comprising a spacer sized and shaped to fitwithin the box and supportable by the bottom panel and having aplurality of passages allowing fluid communication among the containerventilation openings.
 11. The container of claim 10, the spacer beingformed by a plurality of inter-engaging cross members forming alattice-type structure.
 12. The container of claim 11, wherein the crossmembers are formed from corrugated paperboard.
 13. The container ofclaim 12, wherein the cross members are movable relative to one anotherto move between a collapsed configuration and an extended configuration.14. The container of claim 10 further comprising a false bottom panelsized and shaped to fit within the box and supportable by the spacer.15. A food storage and shipping container for use in a freezercomprising: a box having a plurality of side walls; a lid; and aventilation hole located in a side panel.